There are a multitude of ways to deal with the accessibility/maintainability issue and aircraft designers now have decades of experience with what works and what doesn't. Probably the most ingenious I've seen is engine removal on the Sabre jet: the entire tail section comes off.
EDIT: It's important to also note that even with podded engines on (sub-sonic) commercial airliners and bombers, they don't take the entire 'pod' off to change out the engine. The engine 'pod' is used for reasons other than pure maintenance.
It shows that low carbon content of the atmosphere is not an insurmountable barrier, the trick is to use a foliated high surface absorption membrane and rely on ambient air movement rather then large air handlers using fans, that is basically what plant leaves are.
Wrong, do some research next time, 4 percent of oil is turned into plastics, specifically liquids associated with natural gasses are very popular for plastics, and plastic consumption is huge and continues to rise even as the transport fuel uses for oil are starting to level off and be supplanted by electrification. If fossil fuel usage is to cease we would certainly need a replacement for plastics as well as the wider petrol-chemical industries feed-stocks.
Quote from: Impaler on 08/24/2016 03:12 amWrong, do some research next time, 4 percent of oil is turned into plastics, specifically liquids associated with natural gasses are very popular for plastics, and plastic consumption is huge and continues to rise even as the transport fuel uses for oil are starting to level off and be supplanted by electrification. If fossil fuel usage is to cease we would certainly need a replacement for plastics as well as the wider petrol-chemical industries feed-stocks.I did and I cant remember where I got the 1% figure from. Yours appears to be more correct. Either way, it is not a major problem compared to just burning hydrocarbons.
Quote from: Elmar Moelzer on 08/26/2016 03:08 amQuote from: Impaler on 08/24/2016 03:12 amWrong, do some research next time, 4 percent of oil is turned into plastics, specifically liquids associated with natural gasses are very popular for plastics, and plastic consumption is huge and continues to rise even as the transport fuel uses for oil are starting to level off and be supplanted by electrification. If fossil fuel usage is to cease we would certainly need a replacement for plastics as well as the wider petrol-chemical industries feed-stocks.I did and I cant remember where I got the 1% figure from. Yours appears to be more correct. Either way, it is not a major problem compared to just burning hydrocarbons.Given the preponderance of plastic world-wide, it'd be interesting to know if it's possible to convert CO2 (or 'greenhouse gases' generally) directly into acrylates, styrenes or other raw materials for plastics production. I imagine anyone who came up with that tech would make a lot of money!!
Quote from: KelvinZero on 08/01/2016 02:01 pmQuote from: Elmar Moelzer on 08/01/2016 12:24 amMeh, at 0.04% CO2 in the atmosphere, you need to move one ton of air (or more than 800 m3) for 400 grams of CO2. So you are unlikely to get any relevant amount of fuel out of this unless you move tonnes of air around. Seems to me like there could be much better ways to use that solar energy than for that.All Horticulture relies on making money off this principle though. ...This.
Quote from: Elmar Moelzer on 08/01/2016 12:24 amMeh, at 0.04% CO2 in the atmosphere, you need to move one ton of air (or more than 800 m3) for 400 grams of CO2. So you are unlikely to get any relevant amount of fuel out of this unless you move tonnes of air around. Seems to me like there could be much better ways to use that solar energy than for that.All Horticulture relies on making money off this principle though. ...
Meh, at 0.04% CO2 in the atmosphere, you need to move one ton of air (or more than 800 m3) for 400 grams of CO2. So you are unlikely to get any relevant amount of fuel out of this unless you move tonnes of air around. Seems to me like there could be much better ways to use that solar energy than for that.
For aviation, the single new technology that will shape the future of aviation is improved lithium batteries.Particularly lithium-air, which (along with electricity's high efficiency and other things) can allow electric flight for just as long as current jet liners. And at the same speeds. And potentially /faster/ speeds than current airliners.Nearer term, really good lithium-ion and lithium-sulfur.
NASA just awarded SBIRs for converting ISRU products (oxygen, methane, hydrogen, water, CO2, etc) into plastics. And since plastics contain carbon, that means from CO2 on Mars.Here are two of them:http://sbir.nasa.gov/SBIR/abstracts/16/sbir/phase1/SBIR-16-1-H1.01-8453.htmlPROPOSAL TITLE: ISP3: In-Situ Printing Plastic Production System for Space Additive Manufacturingandhttp://sbir.nasa.gov/SBIR/abstracts/16/sbir/phase1/SBIR-16-1-H1.01-8191.htmlPROPOSAL TITLE: Compact In-Situ Polyethylene Production from Carbon Dioxide
I agree with you on that one. Better batteries would be an enabling technology for many things related to aerospace. Depending on energy and power density, it might affect the way we do spaceflight too.
I'd like to agree with you on that one - but unfortunately, I don't. There's more to an electric propulsion system than just batteries: There's the advanced ultra-light-weight non-existent high-temperature superconductors you need to supply the battery power to the engines and then there's the engines themselves. As complex as it is, unless the entire propulsion system is as good or better than current highly-efficient, highly-advanced, extremely-bloody-clever, jet engine/pneumatics technologies, it simply isn't going to fly.. (pun intended).
Civil aviation might be able to benefit from hybrid electric technology on certain classes of aircraft.
Quote from: CameronD on 08/28/2016 10:46 pmI'd like to agree with you on that one - but unfortunately, I don't. There's more to an electric propulsion system than just batteries: There's the advanced ultra-light-weight non-existent high-temperature superconductors you need to supply the battery power to the engines and then there's the engines themselves. As complex as it is, unless the entire propulsion system is as good or better than current highly-efficient, highly-advanced, extremely-bloody-clever, jet engine/pneumatics technologies, it simply isn't going to fly.. (pun intended). Agreed battery powered airliners are not going to happen anytime soon if ever.We might be see hypersonic transport long before we see a fully electric airliner.Civil aviation might be able to benefit from hybrid electric technology on certain classes of aircraft.I also consider fully electric long haul trucks impractical as well though these can benefit from series hybrid technology like what's found on the Chevy Volt.
Quote from: Patchouli on 08/28/2016 11:02 pmQuote from: CameronD on 08/28/2016 10:46 pmI'd like to agree with you on that one - but unfortunately, I don't. There's more to an electric propulsion system than just batteries: There's the advanced ultra-light-weight non-existent high-temperature superconductors you need to supply the battery power to the engines and then there's the engines themselves. As complex as it is, unless the entire propulsion system is as good or better than current highly-efficient, highly-advanced, extremely-bloody-clever, jet engine/pneumatics technologies, it simply isn't going to fly.. (pun intended). Agreed battery powered airliners are not going to happen anytime soon if ever.We might be see hypersonic transport long before we see a fully electric airliner.Civil aviation might be able to benefit from hybrid electric technology on certain classes of aircraft.I also consider fully electric long haul trucks impractical as well though these can benefit from series hybrid technology like what's found on the Chevy Volt.Fully electric airliners are way easier than hypersonic transport.Fully electric long haul trucks are being designed and built by Tesla right now. Provided you can have a big enough battery and have good enough charging infrastructure, there's absolutely no reason fully electric long-haul trucks would be impractical. In fact, due to their being driven a lot more than commuter vehicles, the potential for cost reduction is greater.
Battery technology is already much more advanced that most people in this realm realize. Batteries are still considered second-class.Which is why the electric airliner will catch those folk (who should know better) by surprise. Again. That's why I think even better batteries will dramatically shape the future of aviation.